pNFS, 61 th IETF, DC1 pNFS: Requirements 61 th IETF – DC November 10, 2004

pNFS, 61 th IETF, DC2 Now  Goal Now: requested data moves through NFS server Goal: reply from NFS server enables parallel access to diverse storage servers (NFS, iSCSI, FC, …) Client Host Net Storage Net NFS Server Storage Servers NFSv4 Client Host Net Storage Net NFS Server Storage Servers NFSv4

pNFS, 61 th IETF, DC3 pNFS Requirements In response to pNFS Problem Statement –Draft-gibson-pnfs-problem-statement-01.txt Bandwidth & capacity scaling –Beyond one network endpoint for file system –Server bypass for client access to storage NFSv4 minor extension desired Extensible storage (backend) protocols –NFSv3, NFSv4, SCSI blocks, SCSI objects

pNFS, 61 th IETF, DC4 pNFS Reqs - NFS extensions Industry-wide open standard NFSv4 minor extension desired –No change to existing commands/results –New operations added via compound –Complimentary to, no dependence on RDMA

pNFS, 61 th IETF, DC5 pNFS Reqs - Scalability Respond to scalable cluster computing Scalable bandwidth wrt to total resources –Aggregate BW to files in one FS, one directory –Individual BW to single large files –Employ multiple network endpoints at storage Scalable capacity wrt to total resources –Size of FS, directory, file can scale with storage

pNFS, 61 th IETF, DC6 pNFS Reqs - Interoperability pNFS endpoints talk to non-pNFS NFSv4 Storage protocol interoperability –Well defined storage protocol standards –Multiple different storage protocols, extensible SBC (SCSI blocks), OSD (SCSI objects), NFSvX Separability of storage protocols –NFSv4 extension operation does not need to interpret “layout state” specific to storage

pNFS, 61 th IETF, DC7 pNFS Reqs - Concurrent Sharing Many clients access storage at same time –At device and file level Change visibility can be asserted by client –Data & attribute change visibility not always determined No assertion of client cache coherence –Logic modeled on Direct access mode

pNFS, 61 th IETF, DC8 pNFS Reqs - Recovery Seek simple semantics to enable less complex implementations, interoperability –Slow recovery permissible, fast recovery possible Client recovery may be “notify & retry” –Retry may be equivalent operation using only NFSv4 –Storage operations should be idempotent

pNFS, 61 th IETF, DC9 pNFS Reqs - Security Security comparable to NFSv4 allowed Security model for storage must be well defined –Trusted storage environments not ruled out, but must be well documented –Files: ACLs consistent over servers –Objects: OSD secure capabilities –Blocks: SAN access control tools (zoning, FC ACLs)

pNFS, 61 th IETF, DC10 pNFS Reqs - IANA Need to name storage protocols Divide namespace –1) Reserved for this standard to define –2) Reserved for vendor defined –3) Open for in-house customer defined, non- unique Storage naming defined by storage protocol